The Old Lady have appointed former Italy manager Spalletti to lead the team for the remainder of the campaign.
The experienced coach takes over from the Croatian manager, who was let go post the Lazio setback last weekend.
Tudor arrived at the club in March as Thiago Motta's replacement but left after seven months at the end of an eight-match winless run.
Spalletti guided Napoli to the Serie A crown in 2022-23 then moving on to lead the Italian national team, who had failed to qualify for the 2022 World Cup during Roberto Mancini's tenure.
Under his guidance, they made it to Euro 2024 but were eliminated in the round of 16 by Switzerland.
Nonetheless, Italy dismissed Spalletti in June post a qualifying defeat against Norway, putting Italy in danger of missing a third straight World Cup.
Spalletti has also managed Inter Milan, Roma and Udinese in Serie A and secured two Russian Premier League titles with Zenit St Petersburg.
Massimo Brambilla served as interim manager for Juventus for their 3-1 win against Udinese on Wednesday which left them seventh in Serie A - trailing leaders Napoli by six points after nine matches.
They are 25th in the league phase of the Champions League, after recording one defeat and two ties in the initial three fixtures.
